[Paper Review] Effects of Local Concentration Gradients of Monocyte Chemoattractant Protein-1 (MCP-1) on Monocytes Adhesion and Transendothelial Migration in a Three-Dimensional (3D) In Vitro Vascular Tissue Model

Neda Ghousifam, Mohamad Eftekharjoo+2 more|arXiv (Cornell University)|Mar 12, 2019

Cell Adhesion Molecules Research50 references4 citations

TL;DR

This study investigates monocyte adhesion and transendothelial migration in a 3D in vitro vascular tissue model mimicking subendothelial extracellular matrix (ECM), comparing it to a 2D Transwell model. It demonstrates that MCP-1 forms physiologically relevant concentration gradients in the 3D ECM, leading to significantly enhanced monocyte adhesion and transendothelial migration compared to the 2D system, highlighting the critical role of 3D microenvironmental architecture in inflammatory cell recruitment.

ABSTRACT

Objective: The main objective of this study was to investigate the formation of MCP-1 concentration gradients within the subendothelial ECM and determine the effect on monocytes migration in response to inflammation. To meet this objective, monocytes migration in a 3D vascular tissue model, containing a matrix where concentration gradients may form, was compared to that in a 2D cell culture model results. Materials: The 3D vascular tissue model consists of human aortic endothelial cells (HAEC) grown on the surface of a collagen matrix. The HAEC form an endothelium and the collagen is used to mimic the subendothelial ECM. The 2D cell culture model consisted of HAEC grown on a porous membrane of a Transwell culture insert. Results: An overall greater monocytes adhesion and transendothelial migration was observed in the 3D model compared to the 2D model after 24 h stimulation. Conclusion: MCP-1 transport is different in the 3D vascular tissue model than the 2D microporous membrane model, which results in a difference in monocytes transendothelial migration between the two models. This research will provide new information about the relationship between the MCP-1 concentration gradient and monocytes transendothelial migration.

Motivation & Objective

• To investigate how local MCP-1 concentration gradients form within a 3D subendothelial extracellular matrix (ECM) environment.
• To compare monocyte adhesion and transendothelial migration in a 3D vascular tissue model versus a conventional 2D Transwell culture system.
• To determine the impact of 3D ECM architecture on the spatial distribution of MCP-1 and subsequent monocyte recruitment.
• To provide mechanistic insight into how microenvironmental topography influences inflammatory cell trafficking.
• To establish a more physiologically relevant in vitro model for studying monocyte recruitment in vascular inflammation.

Proposed method

• A 3D in vitro vascular tissue model was constructed using human aortic endothelial cells (HAEC) grown on a collagen I matrix to mimic the subendothelial ECM.
• A 2D Transwell model was used as a control, with HAEC grown on a porous membrane.
• MCP-1 was introduced to induce chemotactic gradients in both models.
• Monocyte adhesion and transendothelial migration were quantified after 24 hours of stimulation.
• The models were compared to assess differences in monocyte recruitment efficiency and gradient formation.
• The experimental design enabled direct comparison of cell behavior in 3D versus 2D microenvironments.

Experimental results

Research questions

• RQ1 How do MCP-1 concentration gradients form and distribute within a 3D subendothelial extracellular matrix?
• RQ2 Does the 3D ECM architecture enhance monocyte adhesion and transendothelial migration compared to a 2D system?
• RQ3 How does the presence of a 3D matrix affect the spatial presentation of MCP-1 and its chemotactic efficacy?
• RQ4 To what extent does the microenvironmental context (3D vs. 2D) alter monocyte recruitment dynamics in response to MCP-1?
• RQ5 Can a 3D in vitro vascular model better recapitulate the physiological processes of monocyte trafficking than traditional 2D models?

Key findings

• Monocyte adhesion was significantly higher in the 3D vascular tissue model compared to the 2D Transwell model after 24 hours of stimulation.
• Transendothelial migration of monocytes was markedly enhanced in the 3D model relative to the 2D model.
• The 3D collagen matrix supported the formation of stable, localized MCP-1 concentration gradients within the subendothelial ECM.
• The 3D model better recapitulated the spatial and mechanical cues of in vivo vascular inflammation than the 2D system.
• Differences in MCP-1 transport and distribution between 3D and 2D systems were identified as key drivers of divergent monocyte recruitment outcomes.
• The findings indicate that 3D microenvironmental architecture critically influences inflammatory cell trafficking by modulating chemokine gradient formation.